Ziad Taib Chalmers University and Astra Zeneca Göteborg Risk Abstract The word risk is often used and sometimes misused not only in the media and in advertisement but also in scientific publications. I will discuss some concepts and misconceptions related to the notion of risk. Among the questions I will discuss are: What is risk and how do we measure it in a given situation? How do these various measures relate to each other? What valid statistical inference can be made about such measures?